MILWAUKEE, Aug. 10 -- Walks have always enjoyed a secure, time-trusted role as winning's greatest inhibitor -- walks kill, the cardinal rule of pitching goes -- but for the longest time Sunday afternoon, an assortment of wild Washington Nationals pitchers disproved the theory. They walked two batters here, two batters there, until their staff walk total equaled the highest in baseball this season. They walked 13. They almost begged to lose. And still, they couldn't.

At least not until they introduced to the ballgame the one man who's become more toxic than wildness itself. In one minute on the mound Sunday afternoon, Luis Ayala ended a game that no prior measure of shaky pitching could. The 57th Milwaukee batter of the game just so happened to be Ayala's first and the ballgame's last. Gabe Kapler clubbed Ayala's fifth pitch just above the wall in Miller Park's left field corner, giving the Milwaukee Brewers a 5-4, 13-inning win and sending the Nationals back to their clubhouse with a revised understanding of the things they can (and cannot) get away with.

It turns out that you can survive 12 innings and almost four hours of baseball by walking two in the 10th and two more in the 11th. You can survive a starting pitcher who goes six innings and gives up five walks -- especially if he's John Lannan, and untouchable stuff offsets his control problems. (He pitched a no-hitter through five.) You can even survive a blown 4-1 lead, so long as your relievers stabilize, and back-of-the-bullpen pitchers like Jesús Colome and Charlie Manning keep your chances afloat.

But it turns out, too, that you cannot survive Ayala. This loss, his second of the week, dropped his record to 1-8. He has a 6.04 ERA and his confidence is a fraction of what it once was, pitching coach Randy St. Claire said. Until this year, he threw his fastball 80 percent of the time; now, he's throwing it 50 percent of the time, uncertain that it can still work. A reliable setup man in Montreal's and Washington's bullpen since 2003, Ayala this year has become a 6-foot-1 white flag. He appears, the game ends.

"It's very surprising," Manager Manny Acta said. "He's been struggling on and off the whole season -- mostly on now -- and you can't even hide him right now. He comes out there, he comes into situations like this, and he's just not making pitches."

Against Milwaukee, he threw five. The final sinker didn't sink, and Kapler, who had stepped in 0 for 6, demolished the deadlock. Another Miller Park sellout celebrated with a prolonged roar. The Nationals -- despite Lannan's six-inning one-hitter, despite back-to-back home runs in the eighth -- had their third consecutive loss.

In the end, the walks were reduced to a side story, a testament to the fortune that carried the Nationals through the game's first 12 innings. Before Saturday, dating from 2000, teams walking 13 or more had a 6-27 record. The Nationals hadn't walked this many in a game since the franchise moved to the District.

"Walks will kill you eventually," said Manning, who walked batters back-to-back in the 11th. "You know, we've got to clean that stuff up a little bit, work at not putting so many base runners on."

Said St. Claire: "Every one of our pitchers is very lucky today."

Only once did the wildness hurt Washington. In the bottom of the eighth -- just after Austin Kearns and Lastings Milledge mashed back-to-back home runs, building a 4-1 lead -- relief pitcher Saúl Rivera allowed a walk, a single and a walk. With two outs, Acta brought on new closer Joel Hanrahan. Milwaukee catcher Mike Rivera pounced on a 2-2 Hanrahan pitch, driving it into the left field corner, clearing the bases and tying the game.

Given Ayala's track record this season, he deserves no role in such undecided games. But after using every available relief pitcher but Steven Shell, Acta turned to Ayala, a free agent at year's end. With every performance like this one, the 30-year-old decreases his future value. With every loss, the pressure to turn things around ratchets up. Those who've watched Ayala this season believe those circumstances have caused his performance to unravel. "I've pitched very bad, so I've got to work," Ayala said after the loss.

"I think he's putting some pressure on himself with his free agent year," St. Claire said. "You're a professional athlete, you've got a contract coming up. You're a six-year free agent. You're trying to impress people, you know? You're thinking, Hey, I want to have a good year here. So you put pressure to have a good year [on yourself] instead of focusing on getting a job done."